<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<meta http-equiv="X-UA-Compatible" content="ie=edge">
	<title>边框裁剪</title>
	<style>
		div{
			width: 200px;
			height: 300px;
			background-image: url('./img/bg.jpg');
			background-size: 100% 100%;


			-webkit-mask-image: radial-gradient(circle at top, transparent 20px, black 0) ,radial-gradient(circle at bottom, transparent 20px, black 0);
			-webkit-mask-position: top,bottom;
			-webkit-mask-size: 60px calc(100% - 70px);
			-webkit-mask-repeat: repeat-x;
			-webkit-mask-mode: match-source;

			mask-image: radial-gradient(circle at top, transparent 20px, black 0) ,radial-gradient(circle at bottom, transparent 20px, black 0);
			mask-position: top,bottom;
			mask-size: 60px calc(100% - 70px);
			mask-repeat: repeat-x;
			mask-mode: match-source;
		}
	</style>
</head>
<body>
	<div></div>
</body>
</html>